Why are various incarnations of the God on earth?

The body is not important. The important thing is what it is doing. Lord Vishnu took the incarnation of a tortoise, fish, and boar because He could feed the whole world, along with maintaining its dignity, in these forms. Although these creatures are not terrible, their existence is also full of divinity like human beings. By taking birth in tortoise, fish, and boar forms, God has also indicated attachment and sympathy for animal life. 

What Was the First Incarnation of God and Why?

The first incarnation of Lord Vishnu was in the form of a fish. He wanted to save the four Vedas from the demons’ clutches and save fisherman Manu from floods. It was a ploy of Lord Brahma. He knew that people living on the earth would not be able to use the Vedas until they are purified. He thought that people’s social values had wholly degenerated, so there was a need to re-establish humanity. 

There, he sought help from Lord Shiva to destroy humanity and create a conducive atmosphere for human beings' existence. Lord Vishnu knew about His plan to cause massive floods. Therefore, he took a fish form to save Manu and his wife Shatarupa because the couple would conceive human beings once again.

What Was the Second Incarnation of God and Why?

The second successive incarnation of Lord Vishnu was a tortoise. With this form, he wanted to help devtas from asuras. Although devtas and asuras were cousins, they were at loggerheads all the time. The tension between them went on escalating. As a result of this, Gods were losing their power that they were bestowed on by Saint Durvasa. So, they approached Lord Brahma and asked him for help. Brahmaji meditated Kurma Avatar—the second birth of lord Vishnu for a while and said, “Let us take help from Lord Vishnu. He always helps those who have complete in him.” Lord Vishnu asked them to defeat asuras. He said that they would have to work hard and obtain Amrit (the nectar) by churning the ocean. He asked them to use Mount Mandarachal as a churning stick and Vasuki (king of serpents) as a rope to turn the mountain. But, the question arose: how can devtas move Mount Mandarachal alone? Then, Lord Vishnu said, “I will take the incarnation of a tortoise and bear the burden of the mountain on my back until the ocean is fully churned and nectar is obtained.

What Was the Third Incarnation of God and Why?

The third consecutive incarnation of Lord Vishnu was boar (Varaha). He appeared in this form to save Mother Earth from Hiranyaksha’s clutches. Hiranyaksha was an infuriated devil who wanted to steal the planet and drown it in the cosmic ocean.

Who was Hiranyaksha?

Hiranyaksha was an Asura, who worked as a gatekeeper or Dwarpala of lord Vishnu’s abode, Vaikuntha, in his last birth. Sanat Kumaras rebuked him and his brother for disallowing them to meet Shri Vishnu. The four Kumaras quarreled with the two brothers to let them go inside, but Jay and Vijaya refused them entry. However, after being cursed, when Jay and Vijaya asked Sanat Kumaras to show them mercy. They were told that they would get salvation (moksha) only after being killed by Lord Vishnu in their future births. So, they realized that one must not misuse their powers. Therefore, Vijaya was born, and Jay and Hiranyaksha took the birth as Hiranyakashipu. Both brothers created troubles in three worlds—Deva Loka, Prithvi Loka, and Patal Loka. Later, they became so greedy that they wanted to become more powerful than Gods and misused their powers.

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